text:
Why do some IAPs lack an Intermediate Fix and/or include other fixes between Final Approach Fix (FAF) and Intermediate Fix (IF)?
I have noticed that some Initial Approach Procedures (IAP) do not mention an Intermediate Fix, but they do include at least one fix before the Final Approach Fix. Take, for example, this IAP of the JFK airport. It includes a Final Approach Fix (MATTR) but the one that precedes this (CORVT) is not labeled as Intermediate Fix. Is it always implied that the fix before the FAF is the Intermediate Fix? Another example is this IAP, also of JFK, where JAMCA appears to be the Intermediate Fix but, nevertheless, is not labeled as such.
In addition, there are some IAPs like this which neither include an Intermediate Fix, nor have the last fix (in this case, CEMUG) labeled as FAF. In this particular example, RUSHY, instead of CEMUG, is labeled as FAF.
Is there any rule which I am not aware of and that will help me clarify the above cases?

The rules are quite lengthy -- a 509 page PDF.  They're all spelled out in excruciating detail in the FAA Order 8260.3D, United States Standard for Terminal Instrument Procedures commonly referred to as the TERPS.
It's available for download here.
I would suggest researching your questions there, and returning here if you have a specific question regarding the application of the TERPS.

Thank you Gerry for pointing me in the right direction, I will take it a closer look at the particular order. I will inform if I find something relevant to my question.

You're welcome.  Your question as written is almost too broad. I focused on your need for source when I provided the reference to the TERPS. There are so many variables and rules that it's impossible to generalize. If you can narrow it down to "How does this rule in the TERPS apply in this case?" it will much better fit within the site structure.


text:
Why is LGA's Instrument Approach Procedure VOR-H misaligned with the runway?
I was looking at LGA's Instrument Approach Procedures, and I noticed that on this IAP plate the final segment (CHUGG to MAFAS) is misaligned with the runway. How should I interpret this? Shouldn't be aligned with the runway, in order for the aircraft to be able to land?

Not all approached are aligned with a specific runway; some like this VOR approach into KLGA is not and just uses circling minimums.
It is anticipated that the aircrew will, after reaching the MAP at MDA, visually confirm that they have the intended runway of landing in sight, thence circle to land on it visually at or above the circling minimums published.  The landing runway would be given by ATC or requested by the flight crew thence approved by ATC.
Nonprecision approaches with circling minimums only are quite common.  They are created this way only if:

The final approach course alignment with the
  runway centerline exceeds 30°.
The descent gradient is greater than 400 ft/NM from
  the FAF to the threshold crossing height (TCH). When
  this maximum gradient is exceeded, the circling
  only approach procedure may be designed to meet
  the gradient criteria limits. This does not preclude a
  straight-in landing if a normal descent and landing
  can be made in accordance with the applicable CFRs.
A runway is not clearly defined on the airfield.

See the FAA’s Instrument Procedures Handbook.

Because the VOR facility is not on the runway but it is on the field.
VOR approaches use VOR facilities and in this case DME measurements to identify fixes and get you down. However not all VOR's are stationed in line with runways. As such  the radials may not always precisely align with the runway. In this case its parallel to the runway, in other cases like at my home airport KDYL it may bring you in at a slight angle.
This is also a Circling approach so it not necessarily intended to get you onto runway 13 (note no runway is listed on the plate) its merely intended to get you below the cloud layer and circle into another runway (however if you look at the notes circling to Runway 4 is not available).

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text:
How do designers determine the altitude profiles of neighboring procedures for deconfliction purposes?
I am interested in studying ICAO's Continuous Climb Operations design strategy, however I have some trouble understanding how the procedure designers take into consideration the traffic flow from neighboring arrival procedures, in order to avoid conflicts with their proposed departure procedure (optimized for continuous climb).
Doc 9993 (Draft version) states:

1.1.5.3 Traffic Avoidance. In the most optimum situation, a departure route should be designed in such a way that there is no restriction that prevents an aircraft continuing its optimum flight profile. Both, the arrival (STAR) and the departure (SID) should be de-conflicted laterally or vertically. This optimum situation may not be reachable and therefore a balance must be found between the arrival and the departure routes.

However, even if one makes the assumption that an IAP has a somewhat self-explanatory altitude profile, at least where the glide slope interception begins, this is clearly not the case for STARs. There are charts which do not provide a starting altitude for their depicted arrival procedures, something that makes the estimation of the aircraft's altitude during the route traversal even harder. On top of that, there are arrival procedures that do not have any altitude constraint at all, such as GATBY ONE.
Anything that could point me into the right direction would be more than welcome.

In terminal areas with relatively low traffic levels, it may be simpler for ATC to let each flight climb or descend at their discretion, with verbal restrictions when an actual conflict appears. There is no point in trying to optimize these procedures because they're already pretty much optimal for the few flights that use them.
However, in busy terminal areas, conflicts may be so common that it becomes simpler to chart the expected restrictions and perhaps verbally remove them when a conflict doesn't actually appear for a specific flight. That doesn't mean you will see a restriction on every fix/leg, though, just the ones where procedures cross.

I have some trouble understanding how the procedure designers take into consideration the traffic flow from neighboring arrival procedures

We don't.
We only concern ourselves with terrain and obstacle clearance. Doc 8168 Vol. II I-2-1-1 refers.
Deconfliction is an ATM responsibility, covered in Doc 4444.

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How can a SID's MEA be above its top altitude?
The SID below has a Top Altitude of 5000 feet, but its Minimum Enroute Altitude (MEA) is above 5000 feet. Why?
I am referring to the SID depicted below, from FAA's SID charts (plate and departure route description). As one can see, the Top Altitude is 5000 for this particular SID. Nevertheless, if we take a look at the MEAs of its transition route, we notice values much greater than 5000 feet (8000, 11000 and 15000 feet).
Could someone explain to me the reason behind this?

This is explained for a different SID over on https://aviation.stackexchange.com/q/48915/8730

Although this is an RNAV procedure, it's a hybrid that requires instructions from ATC to get to DEEZZ. It would be the responsibility of ATC to get aircraft to proper altitudes before reaching the sections with higher MEAs. DEEZZ is 30 miles from JFK and procedures for every runway take departing aircraft away from it, so aircraft should have plenty of time to get a higher altitude. There's also a published hold at DEEZZ if needed.

The part that I have difficulty to understand is that this SID's plate instructs the pilot to maintain 5000 (From the SID's description: "expect vectors to DEEZZ, then on track 296 degrees to HEERO. Maintain 5000. Expect clearance to filed altitude/flight level within ten (10) minutes after departure". Why does the description instruct the pilot to maintain a 5000 feet altitude, if the MEA for the transition route at its very beginning is 8000 feet?

@VectorZita Departures need to stay at 5000 to stay clear of other traffic, but they need to be at 8000 to meet the MEA later. It's up to ATC to bridge these requirements, that's why it's a hybrid with radar required.

ATC has their own minimum vectoring altitudes that are below the published MEAs and sector altitudes and on a normal departure, you are just going to do what you are told.  One key thing here is what to do with a comm failure while on vectors and that's the main value of the published top altitude I would say. So if I squawked 7600 while on vectors on this departure I'd climb/maintain 5000 instead of the min sector altitude if it was different, navigating to DEEZZ, then follow the published SID sgmts/alts and starting the climb to my enroute altitude at dep +10.  Or am I missing something?


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How to interpret the published altitudes for each of US STAR procedures?
I have been studying the STAR procedures, as published by FAA, and I am trying to understand the way that the altitudes are defined for each fix/route. Take, for example, CAMRN4 of JFK.
I see the MEA (Minimum En-route Altitude) of the segment from SEA ISLE to BOTON. Then, no altitude restrictions are applied except when reaching HOGGS, where there is an expected altitude of FL180. The next waypoint with a defined expected altitude is CAMRN, with an expected altitude of 11000ft.
What happens in the intermediate segments (HOGGS --> PANZE --> KARRS...) in terms of altitude? When along a controlled arrival, for example in this specific STAR (CAMRN4), how is the altitude controlled between waypoints when nothing is explicitly stated on the procedure diagram?
The main reason I am asking is because I have been trying to understand Arrival/Departure Procedures and I see that altitude information is often sparse or even completely lacking from some of the diagrams.

Some STAR procedures provide altitude limits on them, so ATC would say:

Descend via the X arrival

All of the needed restrictions are published on the chart. Since the CAMRN4 does not provide hard limits (just "expect" altitudes), ATC will provide pilots with altitude restrictions per other traffic and their SOP, such as:

Cross HOGGS at FL180

For most arrival procedures, it wouldn't be critical to restrict altitude at every fix along the route. Any important restrictions would be included. If a fix doesn't list altitude restrictions, then no special restrictions apply. It's up to ATC to provide additional restrictions as required. Once an aircraft gets to the approach phase, altitude becomes more critical, and there will be more restrictions noted.
If you imagine a flight path through space, only two points are required to define a line. You could even consider the top of descent as one of the points, determined by the aircraft's rate of descent. Altitudes at the other points can be determined by that path. A modern Flight Management Computer is able to provide Vertical Navigation guidance, so that an airplane will basically follow that path to cross fixes at the required altitudes. Without this system, pilots would be expected to either manually adjust rate of descent to follow the restrictions, to perform an idle descent to the next restriction. On the CAMRN4, it would be fine by the chart to dive to 11000 after HOGGS, but this would not be expected or efficient. Some arrival procedures may be steeper or shallower than an open descent.
Note that the CAMRN4 says it is applicable to turbojet aircraft only, and pilots should expect FL180 at HOGGS and 11000 at CAMRN.  Pretty much any aircraft on this STAR will be well above that 6000 MEA. If they do happen to be that low, the MEA should keep them clear of the Atlantic City class C that extends up to 4100 ft. Other than that the general minimum altitudes in the area would apply.

So, it is not (theoretically or practically) possible for a pilot to figure out the altitudes by himself without ATC's guidance while navigating through a STAR, if this STAR does not provide hard limits for every fix/navaid, is that right? Also, even for the STAR that you mentioned (JAIKE.THREE), there are some fixes where no altitudes are mentioned (e.g. FUBRR and BUZIE). Doesn't this mean that he will need ATC's guidance for these fixes, at least as far as altitudes are concerned? And how does ATC decide the altitudes when no altitude is determined in the standard procedure?

@VectorZita I will edit my answer to explain more

I have been trying to figure out an explanation or some kind of standardization, but I stumble upon the necessity of a controller's circumstantial "judgement call". I have not been able to track down some set of rules for minimal controller intervention while performing a STAR procedure.

Very detailed and thorough answer, I really appreciate it.

Put the route into skyvector.com
Departure SIE
Route of BOTON, HOGGS, PANZE, KARRS, CAMRN, DPK
No destination.
This takes you out a ways over the ocean.
You would obviously be talking to ATC this whole trip, but you should plan on climbing to FL180 by HOGGS, and descenging to FL110 by CAMRN.
You could ask for other altitudes for weather avoidance, or be assigned other altitudes for whatever reason.
If you lost comm's enroute, you would be expected to fly as cleared and follow the STAR.

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Can a pilot still land if the tower gives confusing Information?
Recently an airplane crashed at Kathmandu airport in Nepal. The people that owned that plane claim that confusing information was given to the pilot by the control tower, and as a result the plane crashed. Conversation between pilot and control tower given here.
Now my question is: if confusing directions are given by the control tower, what should a pilot do? Should they wait for the exact decision and continue flying, or can they decide to make the plane land safely?

Pilot's prerogative is they can do anything they deem necessary to keep the craft and it's passengers safe. So to answer your question, "can they decide to make the plane land safely", yes, regardless of the rest of your question.

Please clear me which part of my question suffering you guys to give an exact answer ?

Not sure why people are VTC. It seems a reasonable question. But the answer is fairly simple: ask them to clarify. Not sure of the regs in Nepal, but unless there's an emergency, at a controlled airport they shouldn't land unless they hear the words "cleared to land, runway XX." If there's any doubt they should ask.

No one in the tower or air traffic control is responsible for the lives and safety of the people on your aircraft but you, the pilot in command. That's why it's called "command". He/she is responsible, and will take the blame (or the credit) for the consequences of the decisions made and the actions taken.  Yes there are rules, and if you violate them, you will probably have to explain why, but you will need a bigger better explanation if you follow the rules and people die as a result.

At or near touchdown on the runway? Ignore it. The last thing any pilot should do in the critical period near runway touchdown is try to determine what a confusing or unclear radio transmission actually meant.
On the other hand, if "at the time of landing" includes two minutes prior to touchdown, up on downwind, or 4  nm out on extended final approach, different story.
What the cutoff is between these two extremes is what we pay pilots for. It's called situation awareness and exercise of good judgment.

If I heard my call sign at or near touchdown I'd probably go around before I even heard the rest of the transmission.

November upmty ump, Garble Garble, ... on fire! ... garble garble....

More likely, "November xxxx, gear up!" or "November xxxx, runway incursion!"

More likely? who cares what's more likely. Without complete or accurate information, you would make critical decisions on what in your opinion is more likely?  What does your overall situation awareness tell you? What's your fuel state? how hard was this approach? What is the weather like? If you don't KNOW what a radio transmission actually meant, then your own SA and judgment is should take precedence over any assumptions about what might be more likely, .... unless you don't have any ...

If somebody is calling me short final or later, it better be because there's an imminent hazard to landing. If I'm on fire, shut up and roll the trucks.

Well, I guess for someone who is pre-loaded to take specific action X, then I guess everyone else should of course only initiate those communications/actions which would make reaction X appropriate...  AFAIK, that is not in the FAA "Expected pilot Reactions to unclear communications" policy.  We make clearing turns to the left first, because the standard is to pass on the right when overtaking. There is no such standard as to what to do when receiving an unclear transmission. It is (and should be) up to the pilots Situation awareness and judgment.

Let us continue this discussion in chat.

If there is a doubt, there’s no doubt:
GO AROUND.

While this may be good advice this answer could be improved by explaining the reasoning behind it.

Question is clear . What reasons I need to add please mention.

@user70421 you should comment under your question not under an answer, nobody will see this.

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How practical might it be, to carry military tanks by helicopter(s) to remote areas?
How practical might it be, to carry military tanks by helicopter(s) to remote areas?
Wikipedia lists the M1 A2 Abrams tank at 65 metric tons.
HeliPress lists the Russian-made Mi 26 copter as being able to carry 56 tons; it’s unspecified as to which type of tons.
Might it be practical to carry in by helicopter a crane of sufficient lifting capacity to assemble “reasonably quickly”, a tank that had been disassembled to weights that could be carried by helicopter(s)? I believe it would be practical to carry in such a crane, & assemble it reasonably quickly.
Then there’s the aspect of what sort of areas might tanks need to be flown to: High elevations permit smaller payloads, as do hotter temperatures. Presuming the helicopter(s) would take off from an aircraft carrier, how far would the flight likely need to be?
Thank you for your attention to this.

Only barely tangential to aviation.

Light tanks can be airdropped from a C-17, which has far longer range than a helo carrying a significant sling load. Flying disassembled tanks into or near enemy territory & then reassembling them sounds like a better concept in a Lego movie (snap-snap-snap, all ready to go) than for modern, highly complex, combat vehicles. Best case, your tank would have to be designed from the start for this sort of reassembly, and airdrop is just easier.

Not to mention that a slow-moving helicopter at low altitude is a big fat target.

Feasibility
The maximum payload of Mi-26 is:

20,000 kg Internal or external load.

The same page lists the following as possible payload for Mi-26:

2x BRDM-2 scout cars, or 2x BMDs, or
1x BMP or,
1x BTR-60/70/80 or,
1x MT-LB

All of the above are armoured vehicles and not classical tanks.
The 2S25 Sprut-SD is a self-propelled tank destroyer or light tank with a weight of 18 tons. So theoretically it could be carried by the Mi-26.
Other similar light tanks could also be carried. Or heavier tanks disassembled and carried (but as mentioned by Ralph J, that may not be very practical). The Mi-26 is routinely used to ferry heavy earth moving equipment to remote location.
With an C-17 or Il-76, main battle tanks can be (and are) easily carried and would be strategically preferable/more practical (see end of answer for more on same). Light tanks/armoured vehicles are also airdropped from the C-17/Il-76 (as mentioned by Ralph J).
Actual Practicality
However, locations where a tank could be practically employed (predominantly plains) would generally make transport by air and (then as required) by road possible. An example which comes to mind, is use of tanks by the Indian Army in Ladakh with induction by air using Il-76/C-17 and then further movement by road (of interest, that Leh airfield from where they are inducted is at 3,256m/10,682ft!, making it no easy feat).
In areas so remote that tanks need to be moved by helicopter, the use of the tanks (and note tanks are tactically best utilised only in more numbers and never in ones/twos) itself may not be feasibly/practical, so making the exercise futile/uneconomic.
Also, just getting the tanks would not be enough as you also need to move the large amount of fuel, ammunition and spares. These are no lesser of a payload in themselves.
So overall most probably not a very practical exercise.

C-17 ferrying Abrams Tank

Video on YouTube
Source: http://armedforcesweekly.com/c-17-globemaster-iii-loading-m1a1-abrams-tank/
Il-76 ferrying T-72 Tank

Source: https://defense-studies.blogspot.in/2016/07/main-battle-tanks-will-stengthen.html?m=1


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When, if ever, did the 767 move to floatsticks?
I was looking over the wiki article on the Gimli Glider and noticed updates exchanged the term "floatstick" where "dripstick" was previously used. I had not heard this term but a little googling about indicates the former is a newer version of the latter, with the advantage being that it doesn't pour fuel out of the tank.
Looking on the web I found a number of references to fueling the 767, and this one is about the 767-200ER (which I believe is the same/super-similar as the -233?). It talks about the "magnetic type dripless fuel measuring sticks" which seems like it is a floatstick. But this is a very recent publication, 2019, so perhaps this refers only to in-service aircraft after modification?
I also found any number of pages and/or reports that referred to it being a dripstick. This included the final accident investigation report. I also found a diagram showing the 767 did use dripsticks, at least at some point, but it is also possible they simply called them that in spite of it being magnetic. Earlier references seem to use "magnetic dripstick" so it might just be confused terminology.
So...

When did floatsticks (magnetic dripsticks) become common in general, not 767 specifically?
Did production 767's ever come with floatsticks from the factory? Always?
If !2, were in-service aircraft updated to use a floatstick?

I would assume that all variants of the B767 came from Boeing with “dripless” fuel measuring sticks.
The final accident report you referenced states that these measuring sticks are designed to be dripless. Elsewhere in the report it states that even though they are “dripless”, they are commonly  called “drip sticks”. (old habits die hard)
The accident aircraft was C-GAUN which was one of the earliest model B767-200 delivered to Air Canada in March 1983.
This is from page 28 of the report:

What's odd about this statement is that they say it does NOT drip fuel and that's why they call it a drip stick. Imagine what the author's brain was doing at that moment in time...

The Fokker F28, first flight 1967, had 3 or 4 dripless sticks that extended from each underwing when turned 90 deg.
There was a square fluid filled inclinometer grid with a bubble (1-7 on one side and A-G on the other if memory serves) in the fuselage hatch where the refuelling controls were and a book in the cockpit to convert the readings into pounds of fuel.
A ‘drip’ reading was required before the first flight every day and had to agree with the uplift and gauges within 3%.


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Under what circumstances can the Initial Climb Area extend more than 2 nautical miles?
While studying of FAA's Instrument Procedures Handbook, I noticed that on page 1-16 (Chapter 1: Departure Procedures) it defines the Initial Climb Area (ICA) as follows:

The ICA is the segment of the departure procedure that starts at the DER and proceeds along the runway centerline extended to allow the aircraft sufficient distance to reach an altitude of 400 feet above DER elevation and to allow the establishment of positive course guidance by all navigation systems. A typical straight departure ICA extends 2-5 NM from the DER along the runway centerline extended. It is 500 feet wide each side of the runway centerline at DER, then spreads out at 15°

However, I can not understand how it is possible for the ICA to extend more than 2 nautical miles, since the maximum horizontal distance covered by an aircraft until it reaches an altitude of 400 feet above DER elevation can be found by using the default minimum climb gradient of 200 feet/NM, which corresponds to 2 nautical miles. For an ICA to extend more than 2 nautical miles, a climb gradient of less than 200 feet/NM would be required, something that violates the rules imposed by FAA.
Could someone point me in the right direction?

Not a pilot, so this is a comment. If the ground at the departure end of the runway goes uphill at a rate of 100'/NM, it would take 4NM of minimum climb rate to finally clear 400 above DER.

@FreeMan Wouldn’t that be 400’ AGL in your case, but 800‘ above DER?

@CptReynolds yeah, that would probably be AGL. As I mentioned, I'm not a pilot so I got some terminology wrong. Don't know what DER is, but it sounded good (to me).

@FreeMan Ah, very well. DER = Departure End of Runway.

even maintaining that gradient usually puts you at an unsafe glide distance from the runway when you finally reach 1000 or 1200 agl so while there may be nothing technically wrong with the climb, it puts you in an unsafe spot immediately afterwards. following the rules requires awareness and a dynamic interpretation that's based on context like conditions and aircraft type

I think I have reached to a conclusion concerning the explanation behind the rules which states that ICA can be extended up to 10NM (TERPS 14-1-6(b) and Instrument Procedures Handbook 1-16).
The first segment of a departure procedure is always a straight departure leg. In FAA
's PBN manual (Order 8260.58A) it states:

PBN Manual 5-2-1a. The ICA is aligned along the runway centerline for the distance required for a climb to 500 feet above airport elevation.

This implies that ICA might not necessarily end at the aforementioned distance, just that up to that distance it has to be aligned with runway's centerline.
In addition, PBN manual states:

PBN Manual 5-1-1c. The maximum allowable VA or VI leg length is 10NM.

And in TERPS:

TERPS 14-3-2 DR DEPARTURE splay outwards 15 degrees relative to the departure course from the end of the ICA. Limit the DR segment to a maximum distance of 10 NM from DER.

What I can decipher from the above, is that the first straight departure leg is considered an extension of ICA, and as such it should be less than 10 NM long.

The definitive reference for this stuff is the TERPS, and it says that the ICA can extend to 10NM(!). See 14-1-6(b):

Length. The ICA length is normally 2 NM, measured from the ICAB to the
  ICAE along RCL extended. It may be less than 2 NM in length for early
  turns by publishing a climb gradient. The ICA may be extended beyond 2
  NM to maximum length of 10 NM. A specified altitude (typically 400
  feet above DER) or the interception of PCG route must identify the
  ICAE.

I may have missed it, but I didn't see anything in the TERPS that explains how to set the length. However, the ICA definition from the IPH says (emphasis mine):

Initial Climb Area (ICA). An area beginning at the departure end of
  runway (DER) to provide unrestricted climb to at least 400 feet above
  DER elevation.

I couldn't find a formal definition of "unrestricted" but in ATC-speak it usually means "go for it" (e.g. ATC Orders 4-3-2(e)(1)). In this context, though, I think it means "no lower limit" rather than "no upper limit". In other words, the ICA will be extended to allow for 'worst case' scenarios where an aircraft's climb rate is extremely limited.
That suggests hot and high airports, and if you look at the ODPs for a famously high airport like Lake County (Leadville), CO (KLXV) at 9,934' MSL you'll see that the departure procedures are indeed almost straight, e.g.
DAVVY ONE, which is more or less straight out for 20NM from runway 34.

Pondlife thank you for your thorough answer. The 'unrestricted climb' reference is a good catch, however (though I might have interpreted this wrong) when you look at the definition of the Obstacle Identification Surface (OIS) from IPH's glossary, it clearly states: "Departure design criteria assumes an initial climb of 200 Ft/NM after crossing the departure end of the runway (DER)". Also, in the case of DAVVY ONE, a mandatory climb gradient of 364’ per NM to 1350 is assigned, so theoretically ICA's End Line will be reached at less than 2 nautical miles of horizontal covered distance.

@VectorZita Yes, there are still details that are unclear and I couldn't find them in the 'obvious' places, like the TERPS. So I certainly don't think my answer is necessarily the full story; maybe someone else will be able to come up with more information.


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Is there an Instrument Flight Procedures database in digital format such as ARINC 424 for Germany?
I am aware that Eurocontrol has an online repository for charts related to Europe's Instrument Flight Procedures. However, I am trying to find these data coded in a digital format such as ARINC 424 or something similar, especially for Germany. The ideal situation would be something similar to FAA's Coded Instrument Flight Procedures.
Could someone point me in the right direction? I also tried to check Jeppesen's website (link) but I keep receiving a "Page not found" error.

Eurocontrol does offer the whole thing as well – albeit not for free as the FAA does. Check out https://www.eurocontrol.int/service/european-ais-database for more information.

thanks for your input, however I couldn't find any data coded in a digital format suitable for processing, such as ARINC 424. They offer at most charts which are, essentially, images. Could you provide an example of coded instrument flight procedures which can be retrieved from ais database (they do not have to be free)?

According to the page I linked in my answer: "Data from ECAC States and beyond includes [… the] full set of aeronautical information data […] including procedures […]." If you read through you come to https://www.eurocontrol.int/database/static-data-operations where it says under the heading "For data users": "[…] the static data can be downloaded in […] ARINC424 format". So you can get the complete instrument flight procedures digitally coded from them. Their webpage isn't very user-friendly I must admit.

Thank you Chris, that was very helpful. Although it does not guarantee that the aforementioned data are anywhere near complete, it is definitely worth checking out.


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Does a straight missed approach require all turns to be less than or equal to 15 degrees?
I am studying ICAO's PANS-OPS 8168 manual, and I am having trouble understanding the criteria applied to straight and turning missed approaches. In the manual, it clearly states:

I-4-6-2 Types of missed approach.
There are two types of missed approach:
a) straight missed approach (includes turns less than or equal to 15 degrees)
b) turning missed approach.

When there is a turn more than 15 degrees, it takes into considerations three cases (1. turn at altitude/height, 2. turn at at fix/facility, 3. turn at MAPt). As far as I can tell, each one of them concerns only a small initial portion of the whole missed approach. An example can be seen in the following picture.

Taking the above points into consideration, I would like to know if the requirement for turns less than 15 degrees does not concern all the legs of a straight missed approach, only those which are between the MAPt and the (potential) Turning Point. In other words, it seems strange to have, for example, only one turn more than 15 degrees near the end of the missed approach, which can be many miles away from the MAPt, and suddenly the whole missed approach to be considered a turning missed approach, instead of straight, with all the subsequent rules of a turning missed approach applied from the MAPt until the last waypoint.

Don't fixate on the 15° limit. In practice, some missed approach holding points are roughly straight (within a few degrees) all the way to the hold, and some are clearly not straight ahead, e.g. behind you. The former is obviously preferred when feasible.

@StephenS thank you for your input. I am asking because there are different rules imposed, depending on the type of the missed approach (straight or turning), so in my opinion it is important that this distinction be clarified.

In a "straight" missed approach, there will only be one "turn", which is just to align you (think wind correction angle) with a radial or such to go directly to the holding point. There won't be multiple legs like there often are for "turning" one.

A straight missed approach can have a combination of both straight and turning parts. The straight part is called the intermediate missed approach, while the turning part is called the final missed approach. When a straight missed approach starts a turn of more than 15°, the turning missed approach criteria applies, as stated in Part I, Section 4, Chapter 6.3.4 of ICAO DOC 8168 Vol. II:

Wherever practical the missed approach track should be a continuation of the final approach track. Missed approaches involving turns are permitted (see 6.4, “Turning missed approach”), but should only be employed when an operational advantage may be obtained.

Take this approach from Ålesund Airport in Norway for example:

In the straight part you have a track change of 6°, which satisfies the criteria for a straight missed approach. This allows a reduced Minimum Obstacle Clearance (MOC) of 30 m, among other things. When AL821 is reached, the turning missed approach criteria is applied, and the MOC is increased to 50 m.


text:
Why not a second airbridge at the back?
Airbridges slow boarding and disembarking because (normally) there's only one door in use. But... why?
Now the most obvious reason would be that it's very easy to have the aircraft pull forward until its door is roughly in line with the bridge, while it's not possible to do that at the back as well, given the differences in fuselage length.
Sure, but I suspect that 90% of all aircraft could be serviced from a set of two possible bridge locations and the existing bridge movement range.
And then one notes that the wing would be an issue, but that's only true if the bridge is in the air. One could just as easily build a "bridge" on the surface, or even underground (I saw a cross-section of the ramp at Pearson, it was like swiss cheese).
Of course that would mean walking down stairs, which is one of the reasons you use a bridge in the first place, but it would mean that anyone with normal capabilities could use it without exiting outside (did that at Pearson too, in the middle of winter).
Such a system would have the added advantage of allowing the Spanish Solution, with three waves, the middle being the cleaning crew.

They do it in NZ. Source: have seen it done for either loading or offloading maybe 30% of flights.

This is clearly NOT a duplicate, if one cares to examine the linked article. Where are the bridges in that thread?

It was tested at Denver airport by United for a few years ultimately the project was scraped due to jet bridge malfunction that lead to wing damage.

The deciding factor arose out of an incident where one of the bridges
  malfunctioned and damaged the wing of Boeing 757, as ANN reported in
  March. United removed the section that failed, and stopped using the
  over-the-wing part on the other four bridges.

(source)
Side parked dual jet bridge terminals did exist in the early jet age but don't appear to be a great use of space and I cant find any evidence they allowed faster board speeds back then. Taxi in and out would always require quite a bit of bridge retraction and a careful tight turn.

(source)
In a lot of cases the rear of the aircraft is used to load on the new food and remove old garbage blocking the rear with exiting and entering passengers could get in the way of the operations during fast turn arounds.

(source)
As you note you could always go under the wing and come back up. In areas where inclement weather is common you would need the ability to keep the whole jetway enclosed. This could get in the way of the wing unless it was either very low or underground, you would then need some form of retractable stair on the end. All in all it could be built but thats a lot of complexity to add into an airport ramp. This means down time for the gate and money lost for the airport. Depending on arrangement the tunnel may also need to be strong enough to support what ever is above it (vehicles, aircraft etc).

In regard to placing one at the back, I can see how the "wing problem" would be a major issue.  A possible alternative would be to borrow an idea from an L1011 that I traveled in from OAK to HNL many years ago.  IIRC, the airbridge didn't go to the front of the plane, instead the cabin entrance was in the middle, allowing passengers to "spread" out and enter the plane slightly faster.  To avoid using a possibly copyright image, I won't link one, but if you google for L1011 Images views of the port side of the plane will show a door just in front of the leading edge of the wing.

Most excellent answer Dave!

Some airlines do this all the time, as in the picture below. The front boarding may be a jetway, or may also be stairs, depending on where the aircraft is parked. The passengers in the front half of the aircraft board at the front, and the passengers in the back half board at the back.
Boarding at the back involves going down stairs, walking on the tarmac, and climbing the stairs pictured here, so they will seat passengers who can't do those things by themselves in the front half of the plane.

But that's not a bridge - in the dead of winter in Churchill you might die. In Toronto they have covered tent-like structures that start maybe 20m from the aircraft and provide heat. But this is not like a bridge.

@MauryMarkowitz: The basic premise of your question, as stated, is "why is there only one door in use?". Anyway, in the case of inclement weather they simply won't use the rear door and board everybody from the front. It's a perfectly reasonable solution for a large part of the world, which clearly doesn't include Churchill in every season.

Back when Mirabel airport in Montreal (YMX) was still used for international passenger flights, they used "Passenger Transfer Vehicles" (PTVs - like at Dulles) instead of airbridges.  It wasn't unusual to see two of them latched to the sides of a large aircraft.
I've also seen two airbridges attached to two front doors of wide body jets.  The front-most one serving first-class and the far aisle of the plane, and the other the close aisle.

Yes, I've seen this too on 380's. But definitely the exception to the rule.


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What's the benefit of grass versus hardened runways?
I was watching a video and realised that this airport operates both grass and paved runways. What would the benefit of grass versus hardened runways?

On the plus side, for the airport operator, grass runways are (obviously) much cheaper when you price out the cost of pavement. A lawn is cheaper to build than a paved parking lot. An airport operator can have the luxury of much wider runways. You do have to do work to control drainage to be able to operate in spring and control water flow during storms etc, but still way cheaper than asphalt.
For the airplane owner, the main benefits of grass are tire wear, and propeller damage. Propellers pick up lots of fine stones even on what looks like smooth pavement.  Doing runups and starting takoff on grass just about eliminates prop dings.
If you're flying taildraggers, the lower traction of grass makes the airplane much less twitchy in its attempts to switch ends while rolling (like pushing a shopping cart backwards). Taildragger pilots who learn and become proficient with ground handling on grass often almost go back to square one the first time they land on a paved runway.
The main downside of grass other, than the massive lawn care task, and limitations on surface load bearing ability that varies with the moisture content and composition of the soil, is inaccessibility during spring thaw (better or worse, depending on how well drained it is), and very poor traction and braking when it's wet. Wet grass is not unlike operating from hard compacted snow.

I suggest to add the possibility to take off in any direction. Early airports were round for exactly that reason, and paving a large round area is out of the question. The faster speeds of modern planes made this less attractive, though.

But the question is mostly a practical one about modern airports and omnidirectional grass strips are unheard of nowadays.  However, overall surface area is a practical consideration and I'll add something about that.

In the Northern US and Canada with the freeze/thaw annual cycles, a grass field is severely limiting and may force a flying school to close down for most of April and May. If there is a commercial operation, they will almost certainly find a way to pay for paving at least one runway.  If a grass field is really busy, mud becomes a problem as well.

There are various reasons to have grass runways, one note to put this in context, at one point in history all runways were grass/unpaved in some capacity so some of this is a legacy thing. A few reasons

Allowing for cross wind landings without a second paved surface (e.g. KCRS)
Practice for people who want to go to and from smaller grass-only strips elsewhere
Some pilots just like flying their old piper cubs from grass
Maintaining pavement can be expensive
Soft field landings are still on the ACS so why not...
Your weird uncle can build one
They are kept as they are for environmental reasons

Other than requiring a second oversized bag of money that can't entirely be replaced with sweat equity, is there anything that would stop the weird uncle from being able to build a paved runway instead?

@DanIsFiddlingByFirelight I guess it depends if he can fit the steamroller down his driveway. That aside there is no regulatory prohibition against it, plenty of private airports have paved strips that are build by the owners. The FAA does not much care about it unless you go to have it charted or want to put an official procedure into it etc.

As an Air Training Cadet, I did some gliding at RAF Benson (Oxford, UK), where they have a grass strip with a static glider tow winch. I was told that the strip was held ready to be used as a diversionary landing for heavy aircraft with failed undercarriages, mainly because grass minimises fire risk.

+1 just for the weird uncle link, but all the rest is also fine.

Depending on the location, grass runways count as "green space" for the purposes of carbon credits.  So do the Runway End Safety Areas.
Airports/clubs have a significant carbon cost, so financially anything that helps offset pollution taxes helps.
Yes, this is definitely a minor reason, but accountants will use whatever loopholes they can, and a grass runway of 500mx20m is 10k square metres of land or ~20 domestic sections.

I have near 400 hours of conventional gear (tail wheel) time and love to fly them off grass runways since the tail wheel/grass combination is much more forgiving. As noted above, the tires hook up with a paved surface more positively and therefore takeoffs, and even more so, landings require much more concentration. Downside of grass is that a good grass runway requires a lot of attention to stay that way. Correct and frequent mowing, fertilization, and over seeding needs to be done every year. Even the type of tires on the lawn equipment influences the quality of the surface. Lastly, keep street vehicles OFF THE GRASS!


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What are the factors that limit how long an aircraft can stay aloft?
The most obvious one is fuel. Many modern military aircraft, however, are capable of refueling in mid-air. Crew fatigue, another obvious one, can also be addressed by rotating a crew out, and is a non-issue in unmanned aircraft.
The question therefore is, what factors would prevent an aircraft from staying in mid-air indefinitely? Are there any such factors that cannot be addressed, and would make it impossible to design an aircraft that could stay up indefinitely, or at least for an exceptionally long time?

Crew fatigue can also be addressed with dextroamphetamine, the so-called "go pills" in use by the military.

Ouch. I know I don't like this comment, but it is truthful.

Note that we can't even build bridges that stay "up" indefinitely without constant maintenance. And we haven't quite yet mastered mid-air maintenance.

Maintenance is probably the biggest issue. What types of maintenance is needed and the failures that not performing those steps will lead to depends on the design of the aircraft.
For example, on a piston engine used in a small aircraft:
The engine will need oil replaced at some point, and unless a system was created to cycle in new oil in-flight this is probably the first thing that will break down after crew and fuel (as you mentioned). Oil breaking down will lead to early failure of the engine.
Fuel and air filters will get clogged, leading to the engine shutting down.
Which leads to engine wear. Eventually piston rings, ignition systems, etc. will wear out.

You can improve your answer by discussing maintenance on the air frame as well (metal fatigue etc). The only reason I say this is because gliders have become so well designed that some can stay in the air indefinitely because they do not use fuel. Similarly, an electric motor is a very low-maintenance power plant, and with increasingly efficient motors and solar panels, I predict it wont be long (a decade?) before someone makes a self-sustaining solar-powered plane. In this case you'll have to fall back to service intervals for the air frame as well.

@MishaP There have already been a few examples of solar powered aircraft being able to stay aloft 24/7.  See my answer for more info and examples.

The pilot.
Seriously. You're it.
For the sake of (absurdist) argument, let's say we build something akin to a U-2 out of ultra-strong, super-lightweight composites - let's make it a pure glider (it's close enough anyway, and now we have no engine or anything to get in the way and fail!), and we'll use only the best-traied factory capuchin monkeys to ensure a perfect assembly so all the parts do their job exactly per design.
We've got a million-plus-hour glider, and we just dropped a hapless victim volunteer pilot off at say 50,000 feet with a top-secret life support system that's going to give them heat, air, water, a nice steak dinner every night, and even take care of that odd human desire not to sit in our own waste products.
You could - in this theoretical wonderplane, ride air currents, thermals, storm updrafts (for the crazy), etc. and stay aloft pretty much indefinitely, but eventually our volunteer is going to get sick of steak, or start getting bed sores/blood clots/cramps from the seat, or just plain get sick of looking for that next updraft to keep the glider aloft.
If we make the whole thing remote controlled with a wind-turbine generator to power the controls we could swap out pilots and possibly keep it going for years, but it's not much of an "airplane" if there's nobody flying it -- just another drone.

Ultimately every other factor you can come up with is going to be subordinate to the endurance of the humans on board - as a lot of the GA pilots I hang out with are fond of pointing out many of us fly in aircraft easily have 4-5 hours of fuel endurance, but most of us only have a 2-3 hour bladder (and no magic steak-serving life support machine. Gotta buy me one of those for Christmas...).

Pilot fatigue is not a limiting factor for Unmanned Aerial Vehicles. In some cases the UAVs are piloted from bunkers where you can easily change pilots in short intervals indefinitely, use bathrooms, eat, and do whatever humans do. In others, UAVs can hold station completely autonomously without any pilot input.

@MishaP Human fatigue is still a factor, even for UAVs (though granted it's much less of a factor - you could have a village of supporting pilots, so you're fine unless a flu epidemic breaks out). Autonomous UAVs push the envelope even further, but they still require some level of monitoring (lest they hold station while a thunderstorm comes through and snaps their wings off). Once the autonomous UAVs are truly 100% autonomous we can then fall back to maintenance and physical factors :-)

Agreed, although at that point I think this question may be changed to "How do we kill that fully autonomous terminator drone bent on exterminating humanity" =).

I'm just a layman, but this is pretty surprising. Consider the Volvo Ocean race, where a team of 9 might sail a 65-foot boat for 10 months straight. A large aircraft could certainly provide more comfort than a 65-foot boat. Can any actual plane (not a glider, the question mentioned refueling) really fly for 10 months (50k hours) straight?

@raptortech97 Theoretically Air Force One can be refueled and remain aloft "indefinitely" if we assume 2 or 3 flight crews aboard (subject to the limits of supplies onboard - food, potable water, etc. of course - again, the humans are the limiting factor). I'm sure there would eventually be a mechanical breakdown (or more likely a series of them) that required the plane to land (or crash), but it's conceivable that the plane could fly for months before that happened...

Oddly enough, a malfunction of cabin heat (it was winter) was probably what brought to end the current endurance record holder, a Cessna 172, at 64 days, 22 hours, and 19 minutes  (which by the way is a great story to read in itself)

If you didn't mention this, I was going to.

Wow. Just wow. That's an amazing story.

The factors and solutions are

pilot: there are a few options

make it an unmanned aerial vehicle (UAV).
and/or make it so it can be intercepted mid flight for crew and supply changes.
and/or make it self sufficient. This would require a massive aircraft if it is even possible, certainly not at the moment (2014), though partial self sufficiency could be doable with today's technology.

fuel: make it solar. Solar aircraft can store energy as altitude and/or batteries to remain aloft at night.  A Solar panel's life is typically considered about 50 years at which time they produce 50% of their original power.  There have been a few examples like the NASA Helios that could stay aloft 24/7.
bad weather avoidance: has to be fast enough to get out of the way
consumables: like oil/grease, etc

use non-contact bearings where you can to reduce the need. You can't replace all of them due to the inherent instabilities of non-contact bearings.  It is particularly problematic with bearings around high power/load shafts such as thrust bearings responsible for preventing the prop shaft from pulling out of the aircraft.
you could also provide systems for replenishing these consumables.

moving parts wear:

limit the number of moving parts. Electric motors can be built with only 1 moving part
provide systems to bring replacements on board and install them with either maintenance droids (yes like the function that R2D2 was supposed to be for), or with maintenance crew that will also need a way on and off the plane.

material fatigue such as parts that are developing fatigue fractures and also materials that suffer weather damage (eg plastics/paint degrading due to UV light or metal corrosion): this one is tough as I can't think of anything to replace a critical structural component such as a wing spar in flight.  Repairs may be able to be made by temporarily providing alternate structural integrity (think of something like scaffolding but providing structural support around the affected area) while in-situ material repairs are made in the area with damage.

Maintenance is the biggest issue. Titan Aerospace offers UAV aircraft that can stay aloft for 5 years at a time.  Basically it can stay in flight until it breaks like the NASA Helios did.  Essentially the current thinking is to make it relatively cheap and unmanned while we figure out the average life expectancy of these things so we can bring them in for repair/decommissioning.

Theory
As voretaq7 notes, the pilots are the first limiting factor here. We can put a submarine crew underwater for 3 months at a time. Could we do the same on a plane? Maybe someday. The International Space Station is an example of what is possible as far as crew rotations. Of course, energy to fly in the atmosphere and external maintenance would pose some problems for an aircraft.
As far as maintenance is concerned, airliners go 500-800 hours between their low level A checks. However, they also undergo routine maintenance at each stop. Mechanical or electronic items that fail are replaced and minor checks are performed. Engines need oil, hydraulic systems need to be replenished.
These are all decisions made as part of the aircraft design process. By making systems more robust, by adding capacity for consumables such as engine oil, these intervals can be extended. Materials such as composites that are less susceptible to corrosion or fatigue can be used. Electric motors need much less maintenance than jet or piston engines, and electricity can come from solar panels.
It really just comes down to the design of a plane. Theoretically, an "indefinite" endurance is certainly possible. It would probably have to be unmanned, but with a robust structural and propulsion design, it could happen. However, everything will fail or wear out eventually, and without a crew or some system to replace components, that will be the limiting factor.
Examples
As far as commercial flights, there is a Wikipedia article that lists the longest scheduled flights by distance, aircraft type, and airline (and also the shortest scheduled flights, just because). The longest duration flight is DAL201, Johannesburg to Atlanta at 16 hours, 55 minutes on a 777-200LR (currently the airliner with the longest range).
With aerial refueling, endurance increases. The B-2 has flown missions of at least 25 hours, with a crew of 2. Landing for a fuel stop (but without engine shutdown), the longest mission is 44 hours. The longest training mission ever was 50 hours. The pilots train extensively in order to be able to fly these missions.
The B-52 has a similar mission and has flown missions as long as 35 hours. Despite being a single seat aircraft, the F-117 has made flights of over 18 hours.
Also notable is the Rutan Voyager, first plane to fly nonstop around the world. The crew of 2 took 9 days to accomplish this.
The Solar Impulse plane is currently in development, and has made a flight of 26 hours with 1 pilot.

There was infact an experiment to keep aircraft up weeks at a time, using nuclear reactors for energy.
I've heard a few versions, but I believe that Americans never quite got it to work, but the Russians did (i heard sources say that most of their crews got irradiated to death in the process), while I've read other sources neither party got it to work, so I'm quite sure who to believe. In any case- virtually unlimited endurance and range.

I guess that would have meant that had they succeeded they could have stayed up for as long as most submarines stay down (which I think is like three months) ... maybe something to try with pilotless drones, where I could imagine that it could stay for pretty longer, engine condition permitting :)
ps. I can't find any good sources on it, but I think that TU Delft was developing a drone for a 365-day mission duration with an environmental surveillance task.
Source 1/Source 2


text:
What backup systems are in place for flaps actuated by sliding block guides?
Looking at this video of a 737's flap extension, it looks like there is just one screw per side driving all of the flaps. Are there any systems in place that will allow the flaps to extend in the event of the linkage failing? What if hydraulics are lost? Also see point 3 on this question for more information about the flap type I am asking about (but generalized answers are welcome).

"What if hydraulics are lost?" Just about every (hydraulically operated) commercial airliner out there has multiple hydraulic systems, and I'd expect them to be arranged in such a way that the failure of a single system won't critically impair safety-critical systems, including control surface deflection systems.

Given the footage in that video (rotating shafts rotating a jackscrew) There are 2 main failure modes I can think of: the linkage to the jackscrew fails or the jackscrew itself fails.
If the linkage fails the flaps will just not work. Jackscrews will hold the position of the flaps making the flaps fail up (not extended). There should be a feedback mechanism to stop the operational set of flaps before the asymmetric flaps affect the flight.
The jackscrew itself is engineered to not fail if properly maintained. There are also multiple jackscrews per wing
When flaps fail up the plane can still land. It just needs a much longer runway to account for the higher landing speed and a brake inspection. For example in this incident a Boeing 737-800 landed (almost) normally.
When flaps won't retract after takeoff the crew will circle back to the airport and land again with the flaps in takeoff position. This is somewhere between flaps full up and flaps in normal landing configuration.

As eluded to in @rachetfreaks answer the backup is the fact that the aircraft is flyable and more importantly can be landed without deploying flaps so a flap malfunction may not be as critical as other emergencies. Even aircraft up to the A380 or 747 in size can be landed without deploying flaps.
When I was doing my training in a PA-28 my instructor and I practiced no flap landings numerous times so that I could get the feel of landing in the event of a flap malfunction. Like any other type of emergency, pilots do practice this.
There is some relevant discussion here as well.


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How and why would one call the cockpit of an A330 inside its nose gear bay?
According to this A330 call panel diagram,

there is an option to call the nose gear bay with the MECH button. Where is the connection for this in the nose gear bay, and what would it be used for? The closest I can find is in this video, where some connections to call the cockpit of a Boeing 777 are shown in the forward avionics bay, presumably to help with communication among maintenance personnel. Whether these jacks are similar to the MECH channel on the A330 I do not know.

I'd hate to be the guy answering that call at FL330!

The fact it's called the MECH channel is a pretty big hint that yes, this is for maintenance personnel.
Ant it's not just the nose wheel bay, there are service interphone connections in several locations.


text:
Airfoil Sections orientation on a Swept Wing
The swept wing on a typical airliner consists of multiple airfoil sections. Are these sections oriented perpendicular to the wing leading edge, or parallel to the longitudinal axis of the fuselage?
Thanks in advance for any thoughts...

In reality for them to perform as indicated on the airfoil data sheet they need to be aligned to the relative wind at that point on the wing.

Obviously for any given aircraft you could sketch the airfoil sections you'd get if you sliced the wing chord-wise (parallel to the longitudinal axis of the fuselage), or the airfoil sections you'd get if you sliced the wing perpendicular to the leading edge.  So, trying to pin down exactly what this question is asking.  Are you asking which of these two sets of airfoils matches the airfoils specified by the naming system as shown on the plans / design specifications?  Or are you asking which of these sets of airfoils is more representative of what the airflow actually "sees"?   Or --?

You need to clarify for which purpose you intend. You can cut a wing in any direction and see an airfoil section. Structure has a different answer than aero, and they are both correct.

In terms of the ribs used to construct the wing, often both, as in the case of the Boeing 737. The inner ribs are parallel to the fuselage while the other ribs are for the most part orthogonal to the leading edge.

In wing diagrams, airfoil shapes for each different wing sections are drawn and their location on the wing described or indicated with an arrow pointing at a line drawing of the wing.  This doesn't indicate its orientation relative to the leading edge.
If you sectioned (sliced) one of these wing section perpendicular to the leading edge and again sliced it parallel to the longitudinal access you would have two different airfoil shapes-only one would be the designed airfoil shape. Would an aerodynamicist design the airfoil shape to be orientated perpendicular to the wing leading edge?

For conventional aircraft designs, the aerodynamicist selects or designs airfoil sections parallel to the x-axis independent of wing sweep.


text:
Please tell me which trainer aircraft is this?
This trainer aircraft was spotted by me on a video on youtube, which said they were at the Lahore Flying Club. I really could not tell what aircraft they were on. If anyone can tell me, that would be great. Its some Cessna but which?
link to the youtube video:

Picture from the video attached.

Its a Zenair Zodiac CH601 XL you can see the registration code on the side and if you watch the video a bit more they show the inside of the cockpit and you see the registration code a bit more clearly, which you can look up here. It appears to be owned by this flying club.


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What do air traffic controllers do on a slow day?
We all know air traffic controllers have one of the hardest, most stressful jobs on the planet... day after day they handle thousands of aircraft with the cool of a seasoned gunfighter and the surgical precision of a Jenga-playing robot.
But what about when there's no aircraft around? Perhaps it's freezing rain and there no chance of an aircraft landing. Or perhaps the (extremely) high volume of flight training at a particular field suddenly drops to nearly zero over spring break. Or maybe fate and luck just got together and no one wants to go to that airport today.
What do controllers do when there's no aircraft in their area, and especially what do they do when there's not likely to be any aircraft for an extended period (1+ hours)

Tetris.  Have you seen mode 6 on their scopes?

I suspect the answer varies widely depending on the country involved. Not being able to get ahold of controllers in third word countries or, for that matter, in Spain when you were the only airplane around used to be a common problem before I retired in 1999.

At some French airfields, when you phone in your flight plan, they say, "If you arrive around 1300 and can't get an answer on the radio, it's probably because the controllers are at lunch."

They play Galaga

The airspace around the world is divided into sectors within a Flight Information Region (FIR) /Air Route Traffic Control Center (ARTCC) / Area Control Center (ACC), which range from very small and tight airspace pieces to larger combinations or enroute sectors. Enroute sectors will usually be larger than Terminal Maneouvering Areas (TMA).
During peak-hours, these sectors will be handled by one controller responsible for each sector. If capacity and traffic flow permit, these sectors can be combined and two sectors will be handled by the same controller.
Below is a picture of the Paderborn Lower Sector, ranging from GND to FL135. This is usually a stand-alone sector which only covers approaches to Paderborn (EDLP) and Dortmund Airports (EDLW).
(Image Source: Own Work - Author: SentryRaven)
If traffic permits, the adjacent sector Hamm Lower from GND to FL115, handling arrivals and departures to Münster (EDDG), will be handed over to the controller responsible for Paderborn Lower. This can also be done vice-versa, where the Hamm Lower controller becomes responsible for the Paderborn Lower sector.

(Image Source: Own Work - Author: SentryRaven)
TMA controllers not only handle IFR aircraft approaching or departing from airfields within their sector, but also any enroute traffic crossing the sector, VFR traffic requesting to cross airspaces which require prior permission and other tasks.
As Chatty already pointed out in his answer, controllers take breaks between working their sectors and sometimes often switch sectors during a shift. A controller working Paderborn Lower during the beginning of his shift can end up working Hamm Lower towards the end of his shift with adequate breaks in between their sessions.
See this related question:
What is the maximum number of planes a controller can control?

In many parts of the world, air traffic control within each FIR is actually further sub-divided into sectors. These sectors can all have their own controllers, but if things are slow then the sectors can be combined together so that a single controller is now looking at an even bigger area. If this happens, they often just take longer breaks between working the position.
So all that to say, just because they controllers are on shift doesn't mean they're actually working traffic the whole time. If things are slow for hours on end, they may only work 40 minutes and then get an hour off or something like that.


text:
What's P-Factor and why does it occur?
Whenever I hear anyone talking about P-Factor, (whether it be single-engine left turning tendencies or multi-engine loss of directional control scenarios), someone always brings up the fact that the descending blade of a propeller generates more thrust than the ascending blade.  I'm wondering why that's the case.
What is P-Factor and why does it occur?

For simplicity, assume a single-engine plane with a two-blade propeller. Just imagine an aircraft is perfectly level and moving forward through the air. The angle of attack on both blades of the propeller would be the same. Now imagine the plane pitches up a bit. One blade's angle of attack will increase and other will decrease.

(source: AOPA.org)
Within reason, the greater the angle of attack, the greater the thrust generated. So one blade (or, to be more precise, a blade on one side of the aircraft) will generate more thrust than the other.

What if the airplane pitches down, the propeller will generate more force on the left side and the airplane will yaw to the right, correct?

Rather than try to do a full ground school session, I'm going to point you at the section on P-Factor in the awesome (free) textbook See How It Flies.
To attempt to paraphrase, it occurs when your aircraft is operating at high angles of attack. Just like the advancing blade on a helicopter produces more thrust because it's heading upwind, the descending blade of the propeller produces more thrust because it has a higher angle of attack relative to the aircraft's motion through the air.

Angle of attack is defined as the angle between the chord line of an airfoil and the relative wind. Now the relative wind is the apparent wind flow opposite the direction of that airfoil movement. The relative wind depicted in these diagrams is for the airfoil we call the wing! Put the relative wind vector for the rotating propeller blades opposite their movement and we have a minimal change in angle of attack change between the ascending or descending blades.

You may reword and reorder your answer so that is is clear from the first sentence that you are talking about propeller blades.


text:
What is the throttle setting of a piston aircraft during cruise?
I am learning to fly nowadays, I am sorry if this sounds like a dump question.
What is the throttle setting of an aircraft during cruise flight?
After stabilizing the flight after climb do i need to turn down the throttle?

Are you asking about a small Cessna, or a large airliner, or something else?

I suspect that it may vary based on the aircraft you are flying.  Can you please provide some clarification about this?

This is a pretty broad topic.  Can you narrow it down to a specific aircraft?

Broadly speaking its what ever you chose it to be. You should always refer to your aircrafts POH for the information specific to your airframe and engine. Beyond the POH there may also be supplemental engine information from the maker.
Generally take off and at least initial climb out occur at full throttle. Then at when you reach your cruising altitude you will throttle back to your cruise power setting and level off.
For example lets take a look at the charts for a PA-28
You can chose your desired power setting based on a desired fuel burn

Then refer to this chart to see your airspeed.

You can then use these numbers for your flight planing, or work backwards to achieve a target airspeed.
For a trainer these numbers tend to be not all that large of a range. My Archer will do a full power climb out at 2650RPM then throttle back to about 2450RPM for cruise. Higher performance aircraft may have larger ranges as well as more complex operating limitations. Some engines have time limits on which they can be at full throttle and most have thermal operating limits if you decide to dance on the mixture lever. Turbo or super chargers may also add an additional level of management to prevent over boosting. Modern digital engine analyzers allow for a level of precision previously unachievable.
AOPA has a decent article on power management over all, you can find it here.
Pro Tip: A lot of small trainers print the engine performance data on the inside of the sun shade so you dont need to thumb through the POH in flight.

+1 for "what ever you chose it to be".  It's much the same as with a car: you can choose to drive in the fast lane, burning lots more gas to get there a bit quicker, or you can ease back and not burn as much.

It depends a lot on the particular aircraft, but generally power is reduced from full climb power to about 65% or 75% power at cruise.
On a typical fixed pitch, piston powered training aircraft like a C152 or C172, you would reduce from full throttle to about 2300-2400 RPM when you level off at cruising altitude.
Keep in mind that a typical piston powered aircraft only makes full rated takeoff power at sea level on a 15 degree C day.
If you depart an airport at at 2000’ on a hot day, you already have less than full power. If you were to climb to 7,500’ with the throttle pushed all the way in, due to density altitude, you only have about 75% power being produced.


text:
Does the FAA intend to discontinue domestic flight plans and switch to ICAO-only on October 1, 2015?
According to someone on the internet, the FAA intends to discontinue accepting domestic flight plans and switch to ICAO-only in October.  I've also heard this around the airport, but been unable to verify it.
The provided link says that the FAA is proposing to phase out domestic plans, but doesn't say that they've committed to it, nor does it give a date.

The FAA is also proposing to implement flight plan filing for civil
  aircraft exclusively under the format used by the International Civil
  Aviation Organization (ICAO).

Is there an official FAA publication that verifies the FAA's intent to stop accepting domestic flight plans on October 1, 2015?

The only AOPA advocacy topic on this was last revised in 2008 so I'm thinking this is someone misinterpreting the FAA link, not an actual proposal.

The link from your question paraphrases and links to “Flight Service Program Changes,” of which the April 13, 2015 7:49:56 AM EDT revision is reproduced below with added emphasis in boldface.

Flight Service Program Changes
Recognizing a shift in users’ preferences for automated services, the
  FAA is changing its Flight Service operation to make it more efficient
  and reduce costs. The agency will continue to maintain the highest
  level of safety.
The changes come as general aviation pilots are transitioning from
  traditional Flight Service assistance to more automated and web-based
  tools to obtain services. Through the use of updated technology Flight
  Service is taking the opportunity to eliminate redundancies and
  underutilized services.
“None of these changes will affect core flight service safety
  functions such as search and rescue, emergency services, Notice to
  Airmen (NOTAM) entry and dissemination, and pilot weather reports,”
  said Steven Villanueva, Deputy Director Flight Service, in the ATO's
  System Operations Service Unit. “We are phasing in the changes to ease
  the transition for users,” he added.
On October 1, 2015, the FAA will consolidate Flight Watch services
  into routine flight services inflight frequencies to eliminate
  unnecessary duplication of service and provide greater convenience for
  pilots. These services provide inflight weather information to pilots.
  After that date, these services will be available on the same
  frequencies that pilots use to open and close flight plans and to
  receive updates on NOTAMs or Temporary Flight Restrictions (TFRs).
  Dedicated Flight Watch frequencies will be decommissioned.
The FAA is proposing to phase out legacy Remote Airport Advisory
  Service. Seven of the airports do not meet the Agency's criteria for
  receiving advisory service. Flight Service is collaborating with our
  user groups on possible impacts and will be posting the proposed
  change in the Federal Register for public comment.
The FAA is also proposing to implement flight plan filing for civil
  aircraft exclusively under the format used by the International Civil
  Aviation Organization (ICAO). Flight plans contain specific
  information relating to the proposed flight of an aircraft and
  controllers use them to provide air traffic services. Today pilots
  file flight plans in the U.S. under either the domestic or ICAO
  format. The use of one format will simplify the process and align U.S.
  flight plans within ICAO standards.
General aviation pilots increasingly have turned to automation in
  recent years to file flight plans and receive pre-flight briefings.
  New technology such as ADS-B is providing more inflight options to
  pilots. Flight Service will incorporate the industry's newest
  technologies and reduce or eliminate other functions to create
  efficiencies and value. The changes to Flight Watch and RAA are the
  first in what is anticipated to be a series of right-sizing
  initiatives surrounding flight services provided to pilots.
Send your comments, questions, and suggestions to us and share your
  thoughts and ideas.
Flight Service National Airspace Initiative (FSNI) Frequently Asked
  Questions (FAQ)

The linked FAQ list contains a question similar to yours, quoted below including the boldface from the original. Note the first sub-bullet under Flight Plan Filing that states the intent but does not provide a specific date.

What changes will be made in the Long Term?
Long term changes are being worked with stakeholders. Increased usage
  of technology and automation and less reliance on human delivered
  services will be considered. These changes include:

Emergency Frequencies — Pilots, when in distress and using an emergency frequency (121.5MHz), will be responded to by an Air Traffic
  Control (ATC) specialist with surveillance capability, improving the
  timeliness of emergency handling.
Flight Plan Filing

Increased automation that will provide a pilot numerous alternatives for flight plan filing, modification, activation and closure
Transition to exclusive International Civil Aviation Organization (ICAO) format for civil aircraft

Search And Rescue (SAR) — Increase automation to include Automated Activation and Closure of flight plans
Relaying Instrument Flight Rules (IFR) Clearances — Flight Service is working with Air Traffic Control (ATC) to develop alternative solutions to enable pilots to talk directly to an air traffic control facility when requesting an IFR clearance.

See also the related Aviation.SE question Will the frequency 122.000 MHz no longer be used for Flight Watch after October 1st 2015?

So, is that a yes?

That is a yes. They are proposing to move away from the NAS FP (FAA Form 7233-1) and require use of the FAA Form 7233-4 (The FAA version of an international flight plan).   The move is hoped for the fall of 2016. The delay was to get all vendors up to speed, and iron out procedures for specialty flight plans like those for the DC SFRA and DVFR etc.

Do you have some specific references for these statements? Something quoting from (and linked to) the FAA would be ideal.


text:
Are Runway Profile Descent charts available to non-121 carriers? If so, where can I find them?
AIM 5-4-2(c) says:

When crossing altitudes and speed restrictions are issued verbally or are depicted on a chart, ATC will expect the pilot to descend first to the crossing altitude and then reduce speed. Verbal clearances for descent will normally permit an uninterrupted descent in accordance with the procedure as described in paragraph b above. Acceptance of a charted fuel efficient descent (Runway Profile Descent) clearance requires the pilot to adhere to the altitudes, speeds, and headings depicted on the charts unless otherwise instructed by ATC. PILOTS RECEIVING A CLEARANCE FOR A FUEL EFFICIENT DESCENT ARE EXPECTED TO ADVISE ATC IF THEY DO NOT HAVE RUNWAY PROFILE DESCENT CHARTS PUBLISHED FOR THAT AIRPORT OR ARE UNABLE TO COMPLY WITH THE CLEARANCE

I'm interested in learning more about these charted descents.  Are these charts publicly available, or are they proprietary to particular carriers (similar to how certain carriers have self-created instrument approaches that only they are approved to fly)?
If they are publicly available, where can I find examples?


text:
Does the FBW system of a passenger aircraft use differential thrust for yawing?
Are there situations where the fly-by-wire system of a commercial passenger aircraft will use differential thrust to yaw? Or is that even possible at all (i.e. do the necessary interfaces exist)?
I imagine it could for instance be useful in the case of a crosswing landing, to maintain full yawing capabilities. Also, I guess the connection between flight controls and the engine control system exists, as it is shown for example by the envelope protection of an Airbus.

First, you need to understand what fly-by-wire is. In layman's terms, FBW separates pilot input from direct mechanic actuation over anything. Yes, control surfaces are still moved due to hydraulic work, but such work is not exercised by the crew over the hydraulic lines which means pilots don't need to apply different "strength" levels over the sidestick or any other input mechanism.
That said, the FADEC (Fully automated digital engine control) does not apply differential thrust to control yaw in situations where crosswinds are encountered. Yaw is a rudder-controlled motion. Applying differential thrust would put too much strain on the airframe and wing structure, not to mention that in addition to inducing yaw, differential thrust also induces a roll along the longitudinal axis of the aircraft
The only reason differential thrust would be encountered on an airliner is more closely related to non-normal operations in which an engine is idled or shutdown and in those cases the yaw motion induced by the asymmetric thrust would be countered with rudder input.


text:
What is the autorotative rate of descent for a Bell 47-H?
I would like to estimate the amount of time a pilot would have before a forced landing after suffering engine failure in a Bell 47-H at 1,000ft. This is for purposes of understanding a historical accident. The pilot in question ran out of fuel so the tanks were empty. Many thanks.

Never flew the -H, but in -G-3B, as I recall about 20 seconds, perhaps 18.  Depends upon temperature, airspeed at the start, etc.

Many thanks for all answers. I'm not sure the exact starting altitude but it seems like tens of seconds is likely. The pilot did manage an autorotative landing.

According to this fairly recent flight test...

As we climbed for an autorotation Sean explained that the yellow line around the bubble effectively demarcates your autorotation options − you can land on anything under the line, you’d be pushing it beyond that. With the inertia of the -23 model blades and their nine-pound tip weights, the entry is smooth and unhurried, the descent at sixty knots bringing up about 1,700 fpm, and the flare stress-free − very different from the crash-bang-wallop engine-offs of the low-inertia world.

Around 1700 feet per minute in auto. The Bell 47 is known to be one of the most forgiving helicopters to autorotate, thanks to the large blades with weights on the tips... what is known as a 'high inertia' rotor system. The opposite is a 'low inertia' rotor system such as the Robinson series, which requires less power in flight, but the lighter blades don't retain nearly as much inertia in an auto, giving one less latent energy to use during the final flare, and a more slender margin of error.
On my daily commute, I used to admire a Bell 47 I'd see out doing traffic reporting duties. An article popped up in the local paper on how that particular 47 lost engine power at 2000 feet... it was fresh out of an overhaul. The 47 was landed with only a ding on one skid... no report on the damage done by the pilot to the mechanic who overhauled the engine, but I suspect it may have been more than a bent skid.

Somebody might be able to provide some actual numbers, but fwiw, you could look for a H-V curve (height-velocity) chart. I can't find one for the 47H but here's one for the 204B.

Wikipedia
It doesn't show any times, but it will show the height and forward speed combinations that should allow for a safe autorotation. Anything outside the red shaded area should be safe. The curves are created by test pilots, but are based on "minimum ability." Of course, that doesn't account for what you have below you to actually land on.

Using some basic physics, distance s, acceleration from gravity a, time t, initial velocity Vo, then:
s = Vo*t + 1/2 a * t^2
Assuming Vo was 0 (straight & level), then you have
1000 ft = 1/2 (32 ft/sec^2) * t^2
Rearranging,
t sec = square root (1000 ft *2 / 32 ft/sec^2) = or about 8 seconds.
Is that enough time to get the blades spun up for autorotation?  I don't know.

You're assuming it would drop like a rock?

Yes in lieu of any other data. In MA we had a state helicopter drop like a brick into a Charles River boat house when it's rotor blades seize up a few summers ago.  Several severe injuries or worse if I recall.

Rotor blades seized? That sounds like no fun at all.

Yes, 4 dead, 2 years ago  https://www.newenglandaviationhistory.com/tag/massachusetts-state-police-helicopter-crash/

Maybe it was longer ago - article says 1995. I had just started flying in 1994, maybe that's why I still recall it.

https://app.ntsb.gov/pdfgenerator/ReportGeneratorFile.ashx?EventID=20001207X03023&AKey=1&RType=Summary&IType=GA  >A MASSACHUSETTS STATE POLICE (MSP) HELICOPTER DEPARTED A HELIPORT WITH TWO CREWMEMBERS & TWO PASSENGERS, & CLIMBED TO ABOUT 600' OVER A RIVER. WITNESSES REPORTED SEEING A PUFF OF "SMOKE" (OR VAPOR) FROM THE ENGINE EXHAUST. THE HELICOPTER WAS OBSERVED TO TURN TOWARD THE RIVER BANK &
DESCEND AT AN ANGLE BETWEEN 45 & 70 DEGREES. WITNESSES STATED THAT THE MAIN ROTOR BLADES WERE EITHER TURNING SLOWLY OR HAD STOPPED PRIOR TO THE HELICOPTER COLLIDING WITH A BOAT HOUSE ROOF.  Rust in fuel

Just a note about this answer, you do not "spin up" the blades for auto rotation, you prevent the blades slowing in the first place, most blades require the outward force on them to keep them from folding up, if they fold up, you don't need to worry about rpm...or anything for that matter.


text:
Tyre wear and land gear shock reduced by wheel spin up
From the answer to the question 'How are forces on the landing gear reduced or compensated for at touchdown?' I note:

"For what it's worth you do not necessarily want to spin up the gear
  before landing for a few reasons. First off you would need to spin up
  the gear to precisely (or at least very close to) the speed that the
  plane was going to touch down at."

And:

"Spinning the gear up can also have a serious gyroscopic effect that
  will affect the handling of the aircraft."

So why is this not a takeoff problem?
You do not need to spin to landing speed to have a dramatic effect. If you start the spin, you have added angular momentum to the wheel. It is much easier to increase angular momentum in a spinning wheel than it is to instantaneously impart it to a stationary wheel. A few scupper cups on the rim of built into the tyre edge would do the job.

"This is a great research paper on the topic that suggests (in their
  conclusion) a pre spin situation would see 1.07% of the wear of a
  static situation."

Sounds like a worthwhile saving on so many aircraft.

I have edited the question to make it a bit more readable as the quotes are from my answer here.

It is not clear what you are asking. Is it just the single question about why gyro forces are not a problem on takeoff? The title refers to shock on landing.

I don't believe there is problem with gyro precession in spinning wheels; it's more of a vibration issue.  On most airliners the brakes are applied automatically after liftoff to stop the mains and the main reason is unpleasant vibrations as the wheels slow down without the damping effect of being pushed into the pavement.  On less complex aircraft pilots are taught to tap the brakes after liftoff to stop the main wheels from shaking (to the extent that they do) as they wind down.
Airliner wheels get statically balanced after tire installation but they don't usually get balanced dynamically like car tires, and there is often minor vibration that is not noticeable while rolling but can be quite noticeable while spinning on a gear leg dangling in the open when the wheel's natural frequency comes into phase with the gear, scaring the crap out of the pax.
Nose wheels are typically stopped by a snubber in the nose gear well upon retraction so they spin down until then.  Being so much smaller, they aren't as big a problem but if the static balance is not good you can get a pretty noticeable vibration under your feet that grows and then declines as the wheels slow down, then stops as soon as the gear is up. If it's bad enough crews will snag it.
Anyway, to have all that mass spinning all the time the gear is out?  Even if there was a simple way to do it, without the usual weight/cost/complexity issues, airlines would probably be forced to dynamically balance their wheel assemblies and purchase hugely expensive equipement.
Cheaper to just let them wear down and recap them.  Aircraft tires can be retreaded indefinitely as long as the carcass is sound.

Wheel vibration is mainly due to flat spot wear. Flight paths aligned with the runway benefit from wheel gyro influence by improved lateral stability, but will not affect descent or ascent aspects of the flight path. Touching the brakes will assist flight paths including banking, Tyre wear is reduced if the blue smoke zone can be avoided. Having the wheels turning even slowly would make a significant difference. Wheel landing speed can be adjusted to suit. I imagine the overall effect should be less tyre wear, more landing alignment stability, less gear stress, and greater passenger comfort.


text:
Does Garmin G300 GPS use true heading or magnetic?
Does Garmin G300 GPS use true heading or magnetic?  Sorry couldn't find this information anywhere else.

This document from Garmin states on page 265 that headings are magnetic headings. Grid lines shown on the terrain display are oriented to True north, but that is the only reference in the manual to true north. All other occurrences of "true" in the manual refer to True Airspeed.
Which is to be expected; nearly all headings in aviation are magnetic headings. Courses can be true or magnetic, but they're converted to magnetic before they're converted to headings. (Yes, grid navigation near the poles uses other than magnetic headings, but those aren't oriented to true north either, and this Garmin doesn't do grid navigation.)


text:
Why don't helicopter change altitude based on variable rotor RPM as opposed to the collective?
AFAIU, helicopter rotors turn at constant RPM and changes lift based on the collective.  Why no have a variable RPM heli?

I would guess that the response is much faster when the rotor pitch is changed. There is a lot of inertia, engine lag, etc that slows response when using the throttle (especially for turbine powered helicopters).

At the small end of the model helicopter world this is done for cost and simplicity of controls; but fixed pitch models typically have large undercambered blades and much less agility and poorer handling in wind than models with a collective pitch head turning at a faster more steady speed and carrying thinner blades.

As some of the comments have mentioned, one of the major issues in using the rotor speed to adjust for lift instead of the collective is purely the speed of the response, but this is not the only one. Some of the issues that you will run into include

A large rotor blade will have a relatively large amount of inertia, which means that it takes a while to speed up or slow down the blade, and this is going to be prohibitive for safe flight
The rotor itself is attached to the engine via a clutch, which allows the rotor to spin freely if the engine quits. This is a requirement for auto-rotation, but it also means that you can't use the engine speed directly to slow the blade down, you'd have to include some sort of additional brake to slow it down if you want to maintain the ability to auto-rotate
Both piston and turbine engines, unlike an electric motor, have a significantly narrower/smaller range of RPMs that they can function at, with different amounts of power at different RPMs. The engines themselves are also limited in how quickly they can speed up and slow down, which means that even if you could speed up or slow down the rotors themselves rapidly, the engine might not be able to function at the required speed.
As the rotor size increases, so does the speed that the tip of the rotor is traveling at. If the tip of the rotor starts generating shockwaves because it has exceeded the speed of sound, you'll have significantly reduced lift and a large increase in sound volume. The tip of a small rotor isn't going to get anywhere close to super sonic, so this isn't a problem.
The tail rotor itself is mechanically connected to the main rotor, and will need to create different amounts of lift to control the yaw of the helicopter. Since you're probably not going to want to descend or ascend every time you turn left or right, you'll still need a variable pitch for the tail rotor. I already have to adjust the pitch of the tail rotor at various times, and it would add additional complexity to the piloting of the aircraft.
The rotor of a real helicopter is moving a much larger volume of air, and the pilot already has to manage the issues caused by it. For example, if I descend too quickly, I can descend into my own rotor downwash, which will not provide lift. If the wind is blowing in the correct direction, my rotor downwash can be blown into my tail rotor, which will cause a loss of tail rotor effectiveness. Having multiple rotors increases the complexity (and likelihood) of this occurring.

I'm sure there's a number of issues I haven't even thought of that would be difficult or impossible to overcome, but this is just the start. Most of these issues don't exist on a small drone because:

It has electric motors that have a much wider torque curve, and a much faster response time, so they can adjust the speed of the rotors quickly.
The rotors themselves have very little inertia, and their speed can be adjusted quickly.
There are multiple rotors, and no tail rotor, so you don't have the mechanical complexity associated with them.
Because of the significantly smaller amount of air that is being moved by a smaller aircraft, you have significantly less aerodynamic complexity. I don't think you're likely to encounter any issues with settling into your own turbulence, for example.
You can't auto-rotate. In a drone, it doesn't matter as much, since there's no one sitting in it, but as a helicopter pilot, I very much want the ability to autorotate.

This is certainly not a complete list of issues, but are just a small subset of issues that I can think of off the top of my head.


text:
What would happen if pilots were locked out of the flight deck?
Imagine in a hypothetical situation that a commercial airliner was left on autopilot at some cruising altitude. Next imagine that all pilots left the flight deck and the door slammed shut behind them (presumably locked). Would they all be completely trapped outside the flight deck or would there be a way to enter should there be a situation like this?

The following article (captain locked out of flight deck while first officer asleep) may serve as a real-life proxy for your scenario: http://avherald.com/h?article=45cd431c&opt=0

The flight deck door lock system is normally turned on while on the ground and remains on for the entire flight. Once the system is turned on, the door DOES lock automatically when closed and can only be opened by the pilots in the flight deck.
If both pilots left the flight deck, the door would lock automatically behind them unless the door lock system was first turned off. There are procedures in place which can allow the door to be unlocked from the cabin in case no one in the flight deck can open it due to incapacitation.
The pilots can also over-ride this unlocking procedure in case they suspect criminal interference or un-authorized entry attempt.  This over-ride feature prevented the Captain of Germanwings 9525 from re-entering the flight deck as the suicidal First Officer deliberately crashed the aircraft killing all on board.

It would have to be an extraordinary situation for both pilots to leave the flight deck, but in any case the doors don't work like that.  They don't automatically lock on closing and have to be locked by a deliberate action from the fight deck side.

The first rule of Fight Deck is: don't talk about Fight Deck.

Lol that made me think of the other golden rule of flying.  What happens in the sim stays in the sim.

In normal operation the flight deck door DOES automatically lock when closed.

Ok I guess it depends on the airplane.  My experience was on CRJs where the basic reinforced door is a simple deadbolt slider operable from the fight deck side only, and a key operable deadbolt that can be operated from the cabin side.  There was no lock-on-latch function.

Was that pre 9/11? I would expect all passenger airliners now have auto lock. All Boeing and Airbus do.

No it was the post 9/11 reinforced door but if I recall there is an optional remote system with a control panel on the center console.  I never saw it in action though.

Not sure about the CRJ but other airliners indeed have a selector switch on the panel to select the autolock mode of the flight deck door. What I don't know is what SOP is for that switch, it may even depend on the operator.


text:
What plane was this hotel room converted from?
The below image is of a converted aircraft now functioning as a hotel of sorts.
I am having trouble identifying the type of the aircraft. It is not on the listing page either. Does anyone know what aircraft this was?

It's a Gulfstream G2 corporate jet.